富营养预增菌液在肉制品沙门菌常规检测方法中替代效果研究

Evaluation on the effectiveness on enrichment broth in the conventional methods of detection for Salmonella from meat products

目的非选择性富营养肉汤(EB)预增菌检测肉制品沙门菌的方法建立。方法评估免疫磁珠分离(IMS)作为常规流程分离食品沙门菌的内质控方法;比较样品经乳糖肉汤(LB)和EB两种预增液分步增菌后常规平板分离与IMS的分离效果;最终实样比较以EB为预增液的替代流程与IMS的检测敏感性。结果应用IMS检测100件用LB和134件EB分步增菌样品的阳性率没有差异(P>0·05);48件肉制品用EB预增的常规平板分离阳性率均高于LB,56件肉制品用EB预增液作常规平板分离的检测敏感性接近IMS(P>0·05)。结论以EB为预增菌的肉制品沙门菌分步检测流程,节省了增菌时间,提高常规平板分离的检测敏感性。

To establish a suitable method for the detection of Salmonella from meat products the non-selective enrich- ment broth （EB） was used as the preenrichment medium and the immuno-magenetic separation （IMS） method used as an internal quality control process for the routine method to detect Salmonella in foods. The effectiveness of bacterial isolation by using both the conventional plating method and the IMS method in which the samples were preenriched with lactose broth （LB） and/ or EB, as well as the sensitivity of protocol to apply EB as preenrichment medium with IMS technic to detect Salmonella from meat products. It was found that there was no significant difference in the isolation rate between 100 samples preenriched with LB and 134 samples preenriched with EB in which IMS technique had been applied to all samples. The positive rate of isolation by conventional plating method with using EB as the pre-enrichment medium was high than that with LB as the pre-enrichment medium for detection of Salmonella from 48 samples of meat products. Meanwhile, the sensitivity of the conventional plating isolation method by using EB as the pre-enrichment medium was similar to that applying the IMS technique for detection of Salmonella from 56 samples of meat products. It is concluded that the protocol by using EB as the pre-enrichment medium for detection of Salmonella from meat products can save the time for enrichment and increase the sensitivity of conventional plating method in isolation of bacteria.